Method of and means for attaching panels to framework



7 Jan. 5, 1943.

E. SCHAEFER I METHOD OF AND MEANS FOR ATTACHING PANELS TO FRAMEWORK 2Sheets-Sheet l Filed Feb. 17, 1938 INVENTOR. 5772652 56/14 6/67- ATTOEY.

0 E. SCHAEFER Jan. 5, 1943.

METHOD OF AND MEANS FOR ATTACHING PANELS TO FRAMEWORK TTORNE 55.

INVENTOR. 5772652 610/12? fez A I I4 I [WM/VI.

Patented Jan. 5, 1943 METHOD OF AND BEAN S FOR ATTACHING PANELS TOFRAMEWORK Ernest Schafer, Fairview Village, Ohio, ass ignor to ErnestGustav Schaeferand Anna Elizabeth Schaefer, both of FairviewVillage,y0hio Application February 17, 1938, Serial No. 190,921

15 Claims. ;(Cl. 296-30) This invention relates, asindicated, to amethod of and means for attaching panels to framework.

Among other objects of the invention are the provision of a method ofand means for firmly attaching panels to framework, whereby streamliningis rendered possible without the use of expensive plant and dieequipment; whereby a smooth outer surface is obtained, entirely freefrom exposed mouldings, canvas fabric, outside,

Theannexed drawings and the following de-.

scriptionset forth in detail certain means and mode illustrating,however, but one of various ways in viii-ch the principle of theinvention may be used.

In said annexed drawings:

1 is a plan view ofthe inner surfaceof a portion of a panel embodyingthe invention;

Fig. 2 is :a plan view of the outer surfaces of portions of two panelsembodying the invention,

and showing the manner in which the panels are associated for buildingup automobile body and 'other structures; v I of the outer surfaces ofthe corner portions of four panels embodying the 1 Fig. 3 is a plan viewinvention;

and secured to a framework in the manner illustrated in Figs. 2, 3, 4'and 5.

Each panel comprises a rectangular sheet of plywood I, shown in thisinstance as consistin of three pliesor laminations and having'secured,as by gluing and/or nailing, to onesurface thereof adjacent the edges'ofthe sheet, wood backing strips 2. Where the sheet 1 is considerablylonger than it is wide, additional 'wood backing strips 3may beprovided.

In preparing the panel for the reception of fastening devices, holes 4are drilled through the plywood sheet I and strips 2 and '3, at suitablyspaced intervals, one of'such holes being shown in Fig. 6. These holesare then counterbored, as shown in Fig. 7, to provide frusto-conicalportions 5 and 6, for the reception-of the nut'shown in Fig.11. g i

In order to avoid splitting of the backing strips 2 and 3 whenthe nutsare inserted in the counterbored holes and subsequently drawn up, thewalls of the counterboredportions 5 and B of the holes are subjected toa charringor branding operation, as by means of a special electrical- 1yheated branding tool 1, shownin the upper portion of Fig. ,8, thebranded portions of the hole being indicated inthe lower portion of Fig.8.

-. Fig. 4 is afragmentary cross-sectional view,

taken on the line 4-4 of Fig. 1;

Fig. 5 is av fragmentary cross-sectional view taken on the line 5-5 ofFig. 2;

Figs; 6, 7 and 8 illustrate. various steps in the shown in Fi 8;

Y'Ifhe'branding tool 1 has a frusto-conical'end 8 provided on its outersurface with a multiplicity of circumferentially spaced ribs 9, which,when thetool is inserted in the opening 4 (Fig. 7) forms correspondingrecesses or flutes ID in the frusto-conical portion 5 of the hole.

A nut H such as shown in Fig. 11, consisting of frusto-conical shank andhead portions l2 and I3, which correspond with the tapered portions 5,and 6 respectively of the hole '4, isthen inserted i into the hole, asshown in Fig. -10. The portion Fig. 10 is a view similar to Fig. 8,but-showin the fastener nut in place;

Fig. 11 is a perspective view of a fastener Ynut which forms one of theessential elements of the invention; i I Fig. 12 is a view similartojFig. 10, but illustrating a, somewhat modified fastener 'nut andmeans for holding the nut inplace; and

nut shown in'FlgrlZ.

Referring more'particularyjto the drawings, a structure embodying theinvention is fabricated Fi 13 is anelevation of the head "end or the 12of thenut is provided on its outer surface with a multiplicity ofcircumferentially spaced rib M which enter the recesses .or flutes Ill,so as to ,p'reventthe nut from turning, when the nut is subsequentlydrawn up, as will be presently described. The nuts H are either pressedinto position in the holes 4 or are driven in by means of a hammer, andeachnut has'a threaded aperure l5 extending axially therethrough for thereception of a bolt I 6.

' After the nuts II have been inserted in the holes l, the outer surfaceof the panel is covered with a sheet of metal l1, and all of the edgesof this sheet are bent or rolled to provide rebent flanges l8," whichengage the rear surfaces of the strips 2, the flanges extending inwardlyto points from a plurality of panels, which are associated 5 adjacentthe holes4 inthe'strips.

The finished panel is now ready to secure to the frame of the'automobilebody or other structure, portions of such frame being shown in Figs. 2,3, 4 and 5, and consisting-in this instance of channel members l9 whichare welded or other-- wise rigidly secured together. Disposed within theframe channels are wooden strips 20. The frame members at the joints, asshown in Figs.

' 3 and 5, are approximately twice the width of l6 are inserted in theholes in the frame members l9 and strips 20 and into the apertures IS inthe nuts ll, being then turned as by means of a screw-driver, to tightlydraw up the nuts. Since the nuts II have shank portions l2 which aretapered oppositely to the taperjof the heads 2| of the bolts I6, adouble wedge effect is secured when the nuts are drawn up, which resultsin the panel beingfirmly held'to the frame. In practice, bolts s indiameter are used, and these will enable each fastener unit to withstanda pull of 3400 pounds, so that only a relatively small number offasteners is required to hold the panels securely in position. For othertypes of installations; smaller or larger fastener units maybe employed,as required. As an extra precaution against the eifects of vibration;lock washers 24 may beemployed underthe heads 2| of the bolts l6. Insupporting the panels on stationary or non-vibrating. objects, however,

these lock washers may be dispensed with.

It will be noted that in securing, the panels to the frame in the mannerjust described, that the flanges ill of the panels are tightly clampedbetween the backing strips 2 and the wooden strips 20 of the frame. Thisclamping of the flanges to the frame is suflicient to support the sheetsI! of the panels, so that suchsheets are relieved of all carryingstrains.

It will be further noted that in rolling the edges of the sheets H, a,small space 25, is left between the plywood sheets I and the metalsheets l1, avoiding metallic contact between the sheets l1 and the nutsH, and thereby eliminating this source of noise and heat transmission.At this point, it may also be noted that small spaces 26 are leftbetween the edges of the assembled panels (Figs. 3 and 5), therebyavoidingmetal to metal contact between the panels and eliminating thissource of noise. These spaces 25 are so small as not to appreciablydetract from the smooth finished appearance of the entire structure, andin fact, the seamed appearance which. they create will, in some types ofstructures, such as inner wall surfaces, enhance the appearance of suchstructures. If desired, however, these spaces or joints may be filled inwhich solder or similar material, where a smooth, continuous surface isrequired. Moreover, except at points the method of constructing andassembling the panel is very simple, it becomes possible to build evensingle units, or a relatively small number of units, to individualrequirements, and in the modern pleasing styles, now found only in theso-called "mass production units, but without the expensive plantequipment required in mass production.

Due to the absence of holes in the metal sheets of the panels, required;in other structures for fastening purposes, this source of wear andcorrosion (at the holes) is eliminated, and ordinary sheet steel maytherefore be used as an outer covering for the panels, with assurancethat this hidden source of wear and corrosion will not have to becontended with. Moreover, the outer metal sheathing may be of anydesired thickness and hardness, limited only by the fact that it isrequired to withstand suflicient bending to form the edge flanges.

Since the metal of the outer covering of the panels is not itselfsubject to strain, any type of ferrous or non-ferrous metal may be usedfor such covering. The use of non-ferrous sheet metals is especiallydesirable, particularly along I the seaboard, where atmosphericconditions tend to rust conventional steels. Non-ferrous metals areusually softer than ordinary steel, and therefore are not suitable forcarrying strains, in present construction methods which require piercingof the outer surface to accommodate exposed fasteners, these holeshaving a tendency to become elongated under strain and vibration.Moreover, since the sheet metal covering is not rigidly attached to theplywood backing of the panel, buckling or weaving due to the difierencein the thermal coeflicients of expansion between the metal and plywood,are avoided. The separate anchorage of the outer metal surface (heldseparately by its flanges l8) and of the plywood (held separately by,the concealed fastening devices) permits the wood and the metal toexpand or contract independently of each other where there is no jointbetween panels, asin Fig.

building of modern streamlined structures, which demand an unobstructedouter surface. Since with changes in weather conditions, without harm toeither the metal 'or the wood.

The plywood of the panels serves both as insulation against heat andsound,-transmission, and as a load carrying member. Plywood, with itslaminated structure, is especially desirable for its strength andresiliency, weight and bulk considered. Heretofore, however, it has beendifficult to hold plywood, since the fibers were usually crushed and therivets or other fastening devices would pull through under strain andvibration. These difiiculties have been eliminated in the presentconstruction by the use of the nuts I l,-with'their large taperedbearing surfaces. The plywood, as used in the present constructlon (1)carries the load and relieves the outer sheet-metal of carrying strains,(2) protects the outer sheet metal panel against damage from within and(3) insulates against heat and cold, and reduces rumbling noise. Ifdesired, however, other types of manufactured board may be used insteadof plywood, and in some cases, especially for curved sections, plasticsmay be used instead of plywood. On certain types of installations, thebacking may be entirely omitted, and a' built-up wood frame, of backingstrips, such as 2 and 3, used, in which the nuts H are directlyembedded.

Due to the'diificulty of working armor plate, armored units haveheretofore been constructed rivets, are usually unattractive inappearance.

ator units, etc.

or otherwise pierced for .the insertion of rivets,

can also be piercedwith bullets, the hardness and toughness of suchplate have heretofore been limited by such working and piercing factors.The present construction permits armorlplate of extreme hardness andtoughness to be used, since such 'platescan be inserted between theplywood backing and the sheet metal outer covering of the panel, withoutrequiring additional se-- curing or supporting means for such armorplate. Moreover, such armor plate will vbe concealed from view, and theentire appearance of the armored structure improved.

In structures used'for transporting perishable goods, extra heat orsound sheet-insulation material is often found desirable, and can beinserted in the panel in the manner described above with reference toarmor plate. I

, Manufacturers and assemblers of baked enamelled 'sheets and plates andother objects have heretofore suffered much loss from the enamelchipping off because of the method of securing such sheets in place at aplurality of isolated points or spots, and because the fasteners had topass through the enamel surface, thereby setting up strains in theenamel at such points By the use of the present invention, sheets orobjects may be enamelled and baked before the wood backing is installed.Since the flange I8 30 is in contact with the frame,throughout itsentire length, the outer surface of the en melled sheet is'relieved ofharmful strains an chipping is thus avoided.

The invention is of particular advantage in the manufacture ofstructures for export, since it provides asimple, strong and effectivemethod of assembling the unit at its destination.

The invention is particularly adapted for the construction of motortruck bodies, trailers, 40 street cars, railroad cars, coaches, shipsboats,

aeroplanes, etc. It is also of use in any i dustry that requires astrong concealed method of fastening, and is valuable in theumanufactureof store fronts, partitions, counters, bar fixtures, soda fountains,factory-built houses, ready made factory buildings, etc. It is also'ofinterest to workers in the finer sheet metals, enamelled sheets andplates, baked objects, armor-plate,' insulation material, wall board andplywood, plastics, manufacture of signs, building of refriger For lightduty installations, or in cases where branding has been somewhatoverdone, a nut .l such as shown in Figs. 12 and/13, may be employedinstead of the nut I l. The head l3 of the nut has formed therein atcircumferentially spaced points, semicircular recesses 3|], throughwhich nails 3| may be driven into'the plywood l and backing strips 2.Such nails prevent the nut from turning, and where they are employed,the holes in the elements'l and 2 need not be branded, and the shankportion H of the nut I need not have ribs formed thereon, although suchribs may be provided as an additional feature, if desired.

Although the units have been described as secured to a frame consistingof channel members, it will be understood that the units may be securedto frames made of other members, such, for example, as angles, woodstrips, etc. I

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the means andthe steps herein disclosed, provided v3 those stated any of thefollowing claims or their equivalent be employed.

I therefore particularlypoint. out and distinct- 1y claim as myinvention:

5 1. A panel comprising backing means comprising wood strips arranged toform a closed framework, a metallic covering for saidbacking means, saidcovering having rebent flanges at all its edges embracing said backingmeans/and nuts extending into said strips, said nuts having broadtapered heads entirelyconcealed by saidcovering. j

2. A panel comprising backing means consisting-of a sheet of plywood andwood strips secured 5 to one surface thereof, a sheet metal covering forthe other surfaceof saidplywood sheet, said sheet metal covering havingedgej flanges embracing said plywoodsheet and strips, and nuts havingtapered portions extending into said plywood and strips, said nuts beingentirely con-.

cealed by said sheet metal covering. f 3; A panel comprisingbacking-means compris ing wood strips arranged to form a closedframework, a metallic covering for said backing means,

and nuts having a tapered portion extending'into said strips, said nutsbeing'entirelyconcealed by' i said covering, and said tapered portion ofsaid nuts having amultiplicity of circumferentially spaced ribs thereon.j

4. In' a'structure of the character described, a frame,'a panel:comprising backing means com prising wood strips, arranged to form aclosed framework, a metallic covering for said backing means, saidcovering havingv flange portions interposed between said strips and saidfra e, and means forjsecuring said panel to said frame, said means beingconcealed by said covering.

5. In a structure of the character described, a a frame, a panelcomprising a backing means comprisinglwoodstn'ips arranged to form aclosed" framework, a metallic" covering for said backing means, [saidcovering having flange portions interpose d between said strips and saidframe, and means for securing said'panel to said frame, said meanscomprising nutslhaving heads concealed .by said dovering, and-taperedshanks extending' into "said strips, and bolts extending through saidframe and into said nuts. 6; In a structure of the character described,a. 1 v

frame, a panel consisting of a sheet of plwood.

' and wood strips secured to the r ar surface. hereof, a metalliccovering for the front surface of said plywood and having flangeportions interposed between said strips and said frame, and

means for securing'said p'anel to-said frame, said means comprisingnutshaving head portions embedded in said plywood and flushwith the outersurface thereof and tapered shanks extending into said strips, and boltsextending through said frame and into .said nuts. 7 z

f7. In a structure of the character described, a

frame, a metal panel having flange portions formed integrally therewithand-spaced therefrom, nuts disposed within the-space between the body ofsaid panel and said flange portions, said nuts being spaced from eachother along the edge portions of I said panels, and means extending Ithrough said frame and into said nuts, said means securing said panel tosaid frame with said flange portions in engagement" with said frame.

' 8. In a structure of the character described, a self-sustaining frame,a panel comprising a framework of wood strips secured to each other, anda metallic covering for said framework, said covering having flangeportions spaced therefrom said strips frame, and means for securing saidpanel to said frame, said means comprising nuts spaced along the edgesof said covering and having heads concealed by said covering and taperedshanks extending into said strips, and through said frame and into saidnuts.

9. In a structure of the character described, a self-sustaining frame, apanel comprising a sheet of plywood and wood strips secured to the rearsurface thereof adjacent all of the edges thereof, and a metalliccovering having flange portions formed integrally therewith and spacedtherefrom, said flange portions interposed between and said frame, andmeans for securing said panel to said frame, said means comprising nutsspaced along the edges of said covering and having heads concealed bysaid covering and tapered shanks embedded in said strips, and boltsextending through said frame and into said nuts.

10. In a structure of the character described, a self-sustaining frame,a panel comprising a framework of wood strips secured to each other anda metallic covering for said framework, said covering having flangeportions spaced therefrom and interposed between said stripsand saidframe, and means for securing said panel to said frame, said meanscomprising nuts spaced along the edges of said covering and having headsconcealed by said covering and tapered shanks extending into saidstrips, and bolts extending through said frame and-into said nuts,

said bolts having heads with portions engagingsaid frame andtapered in adirection opposite to the taper of said nuts. i

11. In vehicle construction, a frame consisting of members secured toeach other and supported by said veh'cle, a covering-for said framecomprising metal panels having flange portions spaced from the bodies ofsaid panels and in engagement with said frame, nuts'disposed adjacentthe edges of said panel and spacedfrom each other along said edges, andbolts extending through said frame and engaging said nuts.

12. In vehicle construction, a body frame conbolts extending sisting ofchannel members rigidly secured together, wooden strips disposed withinsaid channel members, a covering for said frame comprising panels, eachcons ting of a framework of 5 wood strips secured to each other and ametallic covering therefor, said framework coverings having flangeportions interposed between said wooden strips and said frame, and meansfor securing said panels to said frame, said means comprising nutsspaced along the edges of said framework coverings and having taperedshanks extending into said wood strips, and bolts extending through saidframe and wooden strips and into said nuts. 13. In a structure of thecharacter described, a frame, a metal panel having flange portionsformed integrally therewith and spaced therefrom, nuts disposed withinthe space between the body of said panel and saidflange portions, saidnuts being spaced from each other along the edge portions of saidpanels, and means extending through said frame and into said nuts, saidmeans securing said panel to saidframe with said flange portionsadjacent said frame.

a frame, a metal panel having its edges, said flange portions beingspaced from the body of the panel and in engagement with said frame,nuts disposed adjacent the edges of said panel and spaced from eachother along said edges, said nuts having their axes normal to the bodyof said panel and head portions closely adjacent said panel, and boltsextending through said frame and engaging said nuts.

15. In a structure of the character described, a frame, a metal panelhaving flange portions at the edges, said flange portions being spacedfrom the body of the panel and disposed adjacent said frame, nutsdisposed adjacent the edges of said panel and spaced from each otheralong said edges, said nuts having their axes normal to the body of saidpanel and head portions closely adjacent said panel, and bolts extendingthrough said frame and engaging said nuts.

ERNEST SCHAEFER.

